Blender animation glitching in Unity
The animation in the blend file you uploaded set to end at frame 79, whereas the animation continues to frame 119. I would try double checking the length of the animation as well as the start and end frame when it is exported. When I opened your file and played the animation without doing anything it was 'glitchy' when it looped, but changing the end frame fixed it. Your final animation should start at frame 1 and end at frame 119.